/*
* _08LumaQQ - Java _08QQ Client
*
* Copyright (C) 2004 notXX
*                    luma <stubma@163.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package edu.tsinghua.lumaqq.qq.net;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;
import java.nio.channels.DatagramChannel;
import java.nio.channels.SelectableChannel;
import java.nio.channels.SelectionKey;
import java.nio.channels.UnresolvedAddressException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import edu.tsinghua.lumaqq.qq._08QQ;
import edu.tsinghua.lumaqq.qq.packets._08InPacket;
import edu.tsinghua.lumaqq.qq.packets._08OutPacket;
import edu.tsinghua.lumaqq.qq.packets.PacketParseException;

/**
 * 基于UDP端口通信的QQ端口
 *
 * @author notXX
 * @author luma
 */
public class UDPPort extends AbstractPort {
    /**
     * Log类
     */
    private static final Log log = LogFactory.getLog(UDPPort.class);
    /**
     * 数据报channel
     */
    protected final DatagramChannel channel;

    /**
     * 构造函数
     *
     * @param policy  端口策略
     * @param address 服务器地址
     * @throws IOException 如果构造端口失败
     */
    public UDPPort(IConnectionPolicy policy, InetSocketAddress address) throws IOException {
        super(policy);
        channel = DatagramChannel.open();
        channel.configureBlocking(false);
        this.remoteAddress = address;
    }

    /* (non-Javadoc)
      * @see edu.tsinghua.lumaqq.qq.IPort#channel()
      */
    public SelectableChannel channel() {
        return channel;
    }

    /* (non-Javadoc)
    * @see edu.tsinghua.lumaqq.qq.net.IPort#start()
    */
    public void start() {
        try {
            channel.connect(remoteAddress);
        } catch (UnknownHostException e) {
            log.error("未知的服务器地址");
            processError(new Exception("Unknown Host"));
        } catch (UnresolvedAddressException e) {
            log.error("无法解析服务器地址");
            processError(new Exception("Unable to resolve server address"));
        } catch (IOException e) {
            log.error("连接失败");
            processError(e);
        }
    }

    /* (non-Javadoc)
      * @see edu.tsinghua.lumaqq.qq.IPort#receive()
      */
    public void receive() throws IOException, PacketParseException {
        receiveBuf.clear();
        for (int len = channel.read(receiveBuf); len > 0; len = channel.read(receiveBuf)) {
            receiveBuf.flip();
            _08InPacket packet = policy.parseIn(receiveBuf, false);
            if (packet != null)
                policy.pushIn(packet);
            receiveBuf.clear();
        }
    }

    /* (non-Javadoc)
      * @see edu.tsinghua.lumaqq.qq.IPort#send()
      */
    public void send() throws IOException {
        while (!isEmpty()) {
            sendBuf.clear();
            _08OutPacket packet = remove();
            packet.fill(sendBuf);
            sendBuf.flip();
            if (packet.needAck()) {
                channel.write(sendBuf);
                // 添加到重发队列
                packet.setTimeout(System.currentTimeMillis() + _08QQ.QQ_TIMEOUT_SEND);
                policy.pushResend(packet, getId());
                log.debug("已发送 - " + packet.toString());
            } else {
                int count = packet.getSendCount();
                for (int i = 0; i < count; i++) {
                    sendBuf.rewind();
                    channel.write(sendBuf);
                    log.debug("已发送 - " + packet.toString());
                }
            }
        }
    }

    /* (non-Javadoc)
    * @see edu.tsinghua.lumaqq.qq.net.IPort#send(edu.tsinghua.lumaqq.qq.packets._08OutPacket)
    */
    public void send(_08OutPacket packet) {
        try {
            sendBuf.clear();
            packet.fill(sendBuf);
            sendBuf.flip();
            if (packet.needAck()) {
                channel.write(sendBuf);
                log.debug("已发送 - " + packet.toString());
            } else {
                int count = packet.getSendCount();
                for (int i = 0; i < count; i++) {
                    sendBuf.rewind();
                    channel.write(sendBuf);
                    log.debug("已发送 - " + packet.toString());
                }
            }
        } catch (Exception e) {
            log.error(e.getMessage());
        }
    }

    /* (non-Javadoc)
    * @see edu.tsinghua.lumaqq.qq.IPort#send(java.nio.ByteBuffer)
    */
    public void send(ByteBuffer buffer) {
        try {
            channel.write(buffer);
        } catch (IOException e) {
            log.error(e.getMessage());
        }
    }

    /* (non-Javadoc)
    * @see edu.tsinghua.lumaqq.qq.AbstractPort#dispose()
    */
    public void dispose() {
        try {
            channel.close();
        } catch (IOException e) {
        }
    }

    /* (non-Javadoc)
    * @see edu.tsinghua.lumaqq.qq.IPort#isConnected()
    */
    public boolean isConnected() {
        return true;
    }

    /* (non-Javadoc)
    * @see edu.tsinghua.lumaqq.qq.IHandler#processConnect(java.nio.channels.SelectionKey)
    */
    public void processConnect(SelectionKey sk) throws IOException {
        // 没有什么要做的
    }

    /* (non-Javadoc)
     * @see edu.tsinghua.lumaqq.qq.IHandler#processRead(java.nio.channels.SelectionKey)
     */
    public void processRead(SelectionKey sk) throws IOException, PacketParseException {
        receive();
    }

    /* (non-Javadoc)
     * @see edu.tsinghua.lumaqq.qq.IHandler#processWrite()
     */
    public void processWrite() throws IOException {
        send();
    }
}